Muscular Movement and Diseases Flashcards
(170 cards)
1
Q
What is amyotrophy?
A
Loss of muscle bulk
2
Q
What is sclerosis (in the context of ALS)?
A
“hardening” of the corticospinal tract
3
Q
What upper motor neurons are affected by ALS?
A
betz and large pyramidal cell loss
astrocytic gliosis
lateral sclerosis
4
Q
What lower motor neurons are affected by ALS?
A
anterior horn cell loss
spheroid, bunina bodies, and ventral root atrophy
5
Q
What is the effect of ALS on muscles?
A
active denervation and reinnervation, group atrophy, type grouping
6
Q
What are the symptoms of ALS associated with somatic lower motor neurons?
A
weakness, atrophy, fasciculations, cramps
7
Q
What are the symptoms of ALS associated with somatic upper motor neurons?
A
weakness, spasticity, clonus, hyperreflexia/pathologic reflexes
8
Q
What are the symptoms of ALS associated with bulbar lower motor neurons?
A
dysarthria, dysphagia, sialorrhea, palatal droop, tongue weakness, atrophy, and fasciculations
9
Q
What are the symptoms of ALS associated with bulbar upper motor neurons?
A
dysarthria, dysphagia, pseudobulbar affect, jaw clonus, hyperactive gag, snout, glabellar
10
Q
What lab tests can support an ALS diagnosis?
A
electrophysiologic tests (EMG/NCV)
neuroimaging studies (MRI)
muscle/nerve biopsy
blood tests
urine tests
CSF examination
biomarkers (blood/CSF)
11
Q
What is the most common cause of death associated with ALS?
A
progressive respiratory insufficiency and decline in forced vital capacity
12
Q
What genetic mutations are associated with ALS?
A
SOD1 mutation, C9orf72 (oxidative injury)
TAR-DNA binding protein 43 and FUS/TLS (RNA processing)
reduced transporter proteins (excitotoxicity)
13
Q
What is the function of SOD1?
A
Ubiquitously expressed cytosolic enzyme that catalyzes detoxification of superoxide radicals
14
Q
What are the effects of glutamate excitotoxicity on neurons?
A
Repetitive neuronal firing and calcium influx
15
Q
What is the relationship between ALS and neurofilament accumulation?
A
neurofilament accumulation is associated with aging and is a main pathologic feature of ALS and can disturb axonal transport and lead to motor neuron loss
16
Q
What neuromuscular disorderis caused by mutations in UBQLN2?
A
X-linked ALS and ALS/dementia
17
Q
What is the functiono fRiluzole?
A
It is a treatment for ALS that reduces glutamate release
18
Q
What is the best type of treatment for ALS?
A
a multidisciplinary team approach
19
Q
What type of neurons (UMN/LMN) are affected in primary lateral sclerosis? How does the disease progress?
A
Pure UMN
Slowly progressive
20
Q
What type of neurons (UMN/LMN) are affected in progressive muscular atrophy? How does the disease progress?
A
Pure LMN
Slowly progressive
21
Q
What type of neurons (UMN/LMN) are affected in progressive bulbar palsy? Who does the disease normally affect?
A
UMN > LMN (restricted to bulbar area)
usually women > 65
22
Q
What is the pathophysiology of excitotoxicity in ALS?
A
Astrocytes fail to remove excess glutamate from the synaptic space, resulting in excessive firing of motor neurons, increased calcium influx, and ER/mitochondrial stress
23
Q
What are the main mechanisms that contribute to ALS?
A
- glutamate excitotoxicity
- neuro-inflammation
- altered protein degradation
- altered axonal transport
- RNA metabolism errors
24
Q
What symptoms of ALS can be treated?
A
cramps (with gabapentin, baclofen, etc), pain, spasticity (with baclofen, benzodiazepines, etc), sialorrhea (excess saliva), pseudobulbar affect (laughing and crying), respiratory problems, nutritional problems
Also can use mobility aids and adaptive devices
25
What is the function of edaravone?
A neuroprotective drug for ALS that acts as a free radical scavenger that can reduce oxidative stress
26
What is the difference in function between the medial and lateral motor systems?
Medial system - control of body axis and trunk as part of postural control and locomotion
Lateral system - control of limbs during learned or complex movements
27
What is the difference in localization between the medial and lateral motor systems?
Medial - bilateral
Lateral - contralateral
28
What is the path of corticospinal (pyramidal) tract neurons?
Descends from the primary motor cortex (and premotor/somatic sensory areas) through the posterior limb of internal capsule, crus cerebri, pons, and pyramids of brainstem --\> decussates at the medullospinal junction --\> descends through the spinal white matter of the lateral funiculus
29
What are the typical effects of a corticospinal injury in the upper motor neuron?
Contralateral hemiparesis and spasticity contralateral to the lesion
## Footnote
*lesion is at the posterior limb of the internal capsule usually*
30
Where does the rubrospinal tract run?
It descends from the magnocellular red nucleus in the midbrain to the spinal cord
31
What are the functions of the reticulospinal tract?
control of the body axis and trunk during reflex and locomotor activity, also major source of serotonin modulation
32
Where does the vestibulospinal tract originate?
Vestibular nuclei of pons and rostral medulla
33
What region of the reticulospinal tract acts as a neuromodular for serotonin?
reticulospinal axons from the raphe nuclei
34
What are the main destinations of the medial vestibulospinal tract/descending MLF?
lower motor neurons that innervate the neck muscles and stabilize the head
35
Where does the lateral vestibulospinal tract project?
projects ipsilaterally to excite antigravity leg muscles in a three neuron reflex pathway
36
What is the function of the lateral vestibulospinal tract?
Posture and balance
37
What is the effect of damage ot the lateral vestibulospinal tract?
postural instability with a tendency to fall towards the side of vestibular loss
38
What is the general organization of the motor map?
Lateral parts of the motor cortex = facial muscles
moving medially: fingers --\> hands --\> arms --\> trunk--\> legs
39
What is Brodmann's area 4?
The primary motor cortex of the frontal lobe
40
What is the general physiology of the primary motor cortex neurons?
They are more related to triggering muscle force than any specific muscle movement
41
What is the response of the primary motor cortex to injury?
Small injuries can lead to reorganization and different areas can take on functions of the damaged regions
## Footnote
*this is why the "phantom limb" phenomenon can happen*
42
What is the structure and function of the premotor cortex?
Structure: area rostral to Brodmann's area 4, sends dense axonal projections to the primary motor cortex
Function: active in advance of movements, especially active for visually guided movements
43
What is the structure and function of the supplementary motor area?
Structure: medially located
Function: responsive to internally guided sequences of movements (rather than in association with sensory guided movements)
44
What is the motor effect of damage to the cerebellar flocculus?
Gaze evoked nystagmus
45
What is the effect of vestibulocerebellar loss?
postural disorders, trunk ataxia, abnormal vestibulo-ocular reflex eye movements
46
What is the effect of loss of the vermis?
trunk ataxia, gait ataxia, lack of coordination of movement
47
What is the effect of intermediate cerebellar loss?
limb ataxia, overall lack of coordination of movement, reduced hand movements and fine coordination
48
What is the effect of lateral cerebellum loss?
impaired fine motor coordination, skilled hand movements, motor planning, and motor cognition
49
What is ataxia?
drunken or wobbly aspect to movement
50
What is dysmetria?
mis-reaching (usually hypermetria), over-reaching, or past pointing
51
What is decomposition of movements?
separation of multi-joint movements into single joint motions
52
What is intention tremor?
increased trembling of the extremity as a target object is approached
53
What is adiadochokinesia?
inability to make rapidly alternating movements (ex. quick transition between supination and pronation of hands)
54
What are some distinct signs of cerebellar injury?
ataxia, dysmetria, decomposition of movement, intention tremor, adiadochokinesia, inability to adjust movements or learn new movement patterns
55
What is the direct circuit sequence in the cerebellum?
mossy fibers synapse with granule cell dendrite at synaptic glomerulus --\> granule cell with an axon that ascends toward the cerebellar surface to become a parallel fiber, which synapses onto purkinje cells --\> purkinje cells project out of cerebellar cortex to deep nucleus neuron
56
What is the "error" signal of cerebellar circuitry?
A powerful climbing fiber projection from neurons of the inferior olive --\> sends one fiber branch to each Purkinje cell and causes a massive calcium-based prolonged action potential that triggers long term depression
57
What are the major outputs from the cerebellum?
From deep nuclei directly and indirectly to the ventral lateral thalamus --\> projects to motor and premotor cortex
58
What are the basal ganglia?
basal nuclei of the cerebrum that lie under the cerebral cortex that receive input from all of the cerebral cortex
59
What is the cerebral cortex input to the nuclei?
striatum/corticostriate pathway
60
What are the paths of projections through the basal ganglia?
inputs from cerebral cortex to basal ganglia --\> outputs via dopamine receptor containing inhibitor GABA neurons to the internal segment of the globus pallidus and substantia nigra pars reticulata (output nuclei of basal ganglia that go to the ventral anterior and lateral thalamus)
61
What is the effect of excitation of D1 striatal neurons by the motor cortex?
Inhibits basal ganglia output (via direct pathway), leading to disinhibition of the thalamus --\> promotes movement
62
The clinically most important motor pathway is the:
a) anterolateral system
b) corticospinal tract
c) dorsal column/medial lemniscus pathway
d) substantia nigra compact part
e) locus coeruleus
b) corticospinal tract
63
The major output pathway from the cerebellum is relayed via the:
a) basal ganglia
b) corticospinal tract
c) ventral thalamus
d) substantia nigra compact part
e) inferior olive
c) ventral thalamus
64
The major output pathway from the basal ganglia is relayed via the:
a) cerebellum
b) corticospinal tract
c) ventral thalamus
d) substantia nigra compact part
e) inferior olive
c) ventral thalamus
65
The output nucleus or nuclei of the basal ganglia is/are the:
a) substantia nigra pars reticulata and internal segment of the globus pallidus
b) fastigial, globose, emboliform, dentate, and vestibular nuclei
c) ventral thalamus
d) substantia nigra compact part
e) inferior olive
a) substantia nigra pars reticulata and internal segment of the globus pallidus
66
Responses of primary motor cortex neurons differ from those in the premotor areas by being more related to:
a) muscle force rather than movements of objects
b) sequences of internally generated movements rather than muscle force
c) visually guided movements rather than internally generated sequences of movements
d) extrinsic coordinates rather than intrinsic coordinates
e) ipsilateral body parts rather than contralateral body parts
a) muscle force rather than movements of objects
67
The output neuron of the cerebellar cortex is the:
a) granule cell
b) purkinje cell
c) basket cell
d) stellate cell
e) golgi cell
b) purkinje cell
68
After a large hemisphere stroke, the medial motor pathways may still be able to coordinate:
a) contralateral finger movements for grasping
b) dart throwing
c) the pinch grip
d) visually guided hand movements
e) locomotion
e) locomotion
69
A major contrast in signs between cerebellar patients and Parkinson's disease basal ganglia patients, respectively, is:
a) dysmetria verses hypermetria
b) adiadochokinesia versus hypermetria
c) decomposition of movement versus akinesia
d) bradykinesia versus akinesia
e) akinesia versus ataxia
c) decomposition of movement versus akinesia
70
A patient approaches you with his right arm flexed and right leg extended. Your examination reveals some sensory loss; eye movements are normal. What has most likely happened to cause this posture and gait?
a) LMN stroke of the ventral horn gray matter of spinal cord
b) LMN stroke of ventral horn white matter of spinal cord
c) UMN stroke of white matter of internal capsule
d) UMN stroke of gray matter of precentral motor cortex
c) UMN stroke of white matter of internal capsule
71
What is the effect of injury to the dentate nucleus of the cerebellum?
impairs fine movements of hands and feet, motor planning
72
What is the effect of injury to the vestibular nuclei?
loss of pursuit eye movements, dysmetria of VOR, vertigo and dysequilibrium
73
What types of information is carried by the dorsal and ventral spinocerebellar tracts?
proprioceptive and tactile information from the lower limb and trunk
74
Where is information carried from in the cuneocerebellar and rostral spinocerebellar tracts?
from the upper limbs and trunk
75
How many times do each of the spinocerebellar tracts cross?
uncrossed - dorsal spinocerebellar, cuneocerebellar, and rostral spinocerebellar
twice crossed - ventral spinocerebellar
76
What is the general path of neuronal circuitry in the cerebellum?
Mossy fibers from inputs signal to granule cells (excitatory) --\> excites purkinje cells --\> inhibits deep nuclear cell, leading to fine tuning of movements via the thalamus
Climbing fibers also interact with purkinje cells and can activate them orcause long term depression of firing
77
What is long term depression of the cerebellum?
Occurs when climbing fibers provide an error signal when a movement has unwanted or unexpected results --\> leads to decreased strength of synapses that caused the "wrong" movements
78
A patient has dysdiadochokinesia and intention tremor of the right hand. Decomposition of movements is unclear, may be absent. The left hand is normal. There is no obvious postural sway in the Romberg test, no pronator drift, and gait appears normal. Where is the cerebellar lesion?
a) left vermis
b) left intermediate cerebellum
c) left lateral cerebellum
d) right vermis
e) right intermediate cerebellum
f) right lateral cerebellum
f) right lateral cerebellum
79
What is the molecular process of muscle contraction?
membrane depolarizes --\> SR opens and releases calcium --\> calcium binds troponin --\> tropomyosin moves and exposes myosin to actin --\> crosbridge and power stroke
80
What is the effect of neurogenic changes to muscle fibers on fiber arrangement?
Normal muscle = checker board pattern of different fiber types (determined by which nerve innervates the fiber)
If damaged nerve regenerates, the checker pattern is maintained
If the nerve that regenerates is a different nerve, it will innervate a group of surrounding muscle fibers that are all one type (type grouping) --\> looks more patchy than checkered
81
What are the pathological changes of muscle fibers associated with myopathic changes?
fiber type is maintained, but fibers become rounded in appearance
sometimes the fiber size varies, increased internalized nuclei, fatty infiltration, increased connective tissue, and inflammatory infiltrates
82
What is the usual distribution of weakness associated with myopathy?
weakness (without any other symptoms) that is usually symmetric and proximally predominant
## Footnote
*can also be asymmetric and distal for specific types of myopathies*
83
What reflex changes are associated with myopathies? Sensory changes?
Reflexes - usually normal
Sensory - usually normal
84
What are the clinical features of dermatomyositis?
proximal predominant weakness progressing over weeks with characteristic skin lesions (heliotrope rash on face, erythema on trunk and hands)
also includes other systemic features
85
What systemic features are associated with dermatomyositis?
cardiac (conduction defects and arrhythmias), pulmonary (ILD), GI (dysphagia, aspiration, delayed gastric emptying), joints (arthralgias without arthritis), vasculopathy (skin/muscle/GI), malignancy (increased risk), ocular (retinopathy, conjunctivitis, iritis, uveitis)
86
What is the pathogenesis of dermatomyositis?
humorally mediated microangiopathy
87
What are the biopsy findings of inflammatory myopathies?
perifascicular atrophy along with inflammatory cell infiltrates (mainly B cells) in the perivascular and perymysial regions
88
What disease is associated with pathological findings of perifascicular atrophy with inflammatory infiltrates?
Dermatomyositis
89
What is the treatment for dermatomyositis?
immunomodulating therapies (prednisone, methotrexate, etc)
90
What are the clinical features of polymyositis?
similar to dermatomyositis but without skin involvement (proximal predominant weakness, multisystem involvement)
91
What is the pathogenesis of polymyositis?
antigen-specific immune response directed against muscle fibers
92
What are the muscle biopsy findings associated with polymyositis?
endomysial mononuclear inflammatory cells (mainly CD8+ T cells) surrounding and invading non-necrotic muscle fibers
93
What is the clinical presentation of inclusion body myositis?
weakness involving wrist flexor and knee extensor muscles, predominantly in older adults
94
What is the treatment of inclusion body myositis?
supportive care (not responsive to immunotherapy)
95
What is the pathophysiology of Duchenne muscular dystrophy?
X-linked recessive mutation of the dystrophin gene that results in near or total loss of dystrophin protein
96
What is the function of dystrophin protein?
Dystrophin is a sub-sarcolemma protein that serves as a structural link between the intracellular cytoskeleton and extracellular matrix
It stabilizes muscle membrane during contraction and relaxation
97
What is the effect of loss of dystrophin?
muscle membrane disruption from structural failure, rupture and necrosis of muscle fibers, muscle gets replaced by fat and connective tissue
98
What are the clinical features of Duchenne muscular dystrophy?
- usually normal at birth, proximal weakness in legs \> arms by age 2-6, and wheelchair by age 12
- calf hypertrophy
- respiratory function decline
- cardiac involvement
- early rise in CK
99
What are the muscle biopsy findings associated with Duchenne muscular dystrophy?
increased connective tissue, fiber size variability, scattered necrotic and regenerating fibers, immunohistochemistry demonstrates reduced or absent dystrophin on the sarcolemma
100
What are the treatments for Duchenne muscular dystrophy?
corticosteroids
101
What is Becker muscular dystrophy? What are the clinical features?
X-linked recessive mutation of dystrophin gene where dystrophin is semifunctional and of abnormal size and/or amount
Clinical features: similar to DMD, but slower progression and later onset
102
What are the muscle biopsy findings associated with Becker muscular dystrophy?
similar to DMD, but less severe
IHC demonstrates present but reduced dystrophin on the sarcolemma
103
What is limb-girdle muscular dystrophy?
a heterogenous group of muscle disorders that can be dominant or recessive that are similar to the dystrophinopathies
104
What is the pathophysiology of Pompe disease/Acid Maltase deficiency?
autosomal recessive disorder caused by mutation of lysosomal acid alpha-glucosidase
## Footnote
*glycogen is normally degraded in lysosomes by acid maltase to glucose; failure of enzyme results in glycogen accumulation which can displace organelles or lysosomal rupture*
105
What are the clinical features of acid maltase deficiency?
infantile: generalized weakness and hypotonia
adult: respiratory and limb-girdle weakness
106
What is the pathophysiology of myophosphorylase deficiency?
autosomal recessive disorder caused by mutation of gene that encodes myophosphorylase --\> leads to impaired glycolysis during anaerobic activity and glycogen accumulation
## Footnote
*also leads to increased ADP and decreased inorganic phosphate, which can disrupt muscle cross-linking*
107
What are the clinical features of myophosphorylase deficiency?
exercise intolerance in childhood, exertional pain with brief intense (anaerobic) activities, myoglobinuria
108
What are the muscle biopsy findings associated with myophosphorylase deficiency?
subsarcolemmal glycogen collections can be seen with PAS staining; phosphorylase stain shows no activity
109
Why do defects in the transport of long-chain fatty acids and metabolism of lipids lead to myopathies?
long-chain fatty acids are a major source of fuel both at rest and following prolonged activity
110
What are the clinical manifestations of lipid storage disorders?
progressive muscle weakness and hypotonia or recurrent rhabdomyolysis after exercise
111
What is the pathogenesis of steroid myopathy?
corticosteroids bind receptors on target cells, which may result in decreased protein synthesis, increased protein degradation, impaired mitochondrial function, or decreased sarcolemmal excitability
112
What are the clinical features of steroid myopathy?
proximally predominant weakness may develop acutely in the setting of high dose IV corticosteroids, over weeks after starting high dose oral steroids, or slowly with progressive deterioration during chronic corticosteroid ingestion
113
What are the muscle biopsy findings associated with steroid myopathy?
type 2 fiber atrophy
114
What is the pathogenesis of statin myopathy?
HMG-CoA reductase inhibitors block production of cholesterol *and* geranylgeraniol --\> important in production of CoQ10 (ATP production), dolichol (glycoprotein synthesis), isopentyladine (tRNA), and activation of regulatory proteins
115
What are the clinical features of statin myopathy?
ranges from asymptomatic hyper CK-emia to myalgias and mild weakness to severe proximal weakness
116
What are the muscle biopsy findings associated with statin myopathy?
scattered muscle fiber necrosis with phagocytosis and small regenerating muscle fibers
117
What are examples of presynaptic disorders of the NMJ?
lambert eaton myasthenic syndrome, botulism/botulinum toxin, choline acetyltransferase deficiency
118
What are synaptic disorders of the NMJ?
acetylcholinesterase deficiency, organophosphate toxicity
119
What are postsynaptic disorders of the NMJ?
myasthenia gravis, drug induced, toxic
120
What are the clinical features of myasthenia gravis?
fluctuating weakness of any voluntary muscle group, typically worsened by activity or stressors
121
What are the ocular and bulbar symptoms of myasthenia gravis?
ocular: diplopia, ptosis
bulbar dysfunction: speech changes, chewing and swallowing difficulties
122
What are the physical exam findings of myasthenia gravis?
diffuse weakness
eye movement abnormalities
eyelid and mouth closure weakness
speech slurred with nasal quality
respiratory decline
123
What is the edrophonium (tensilon) test?
Administration of a short acting acetylcholinesterase inhibitor that can test for myasthenia gravis (but is not used anymore)
124
What is the treatment for myasthenia gravis?
acetylcholinesterase inhibitors, corticosteroids, immunomodulation, thymectomy (if thymoma or thymic hyperplasia)
125
Damage to what structures results in demyelination?
Schwann cells or myelin sheath
126
What is Wallerian degeneration?
degeneration of the distal portion of a nerve that occurs after injury in a discrete localized event
127
What can occur to a nerve after injury?
It can re-grow either from the injured nerve or a neighboring nerve that sprouts to ennervate the denervated muscle
128
What is the role of Schwann cells in nerve regeneration?
they proliferate and form bands of bungner, which provide a substrate for axonal regeneration
129
What are the general patterns of symptoms in peripheral axonal neuropathies?
symmetric and affect longest nerves first
sensory symptoms predominate, but motor symptoms can occur too
130
What are the general patterns of symptoms for demyelinating neuropathies?
proximal and distal symptoms
131
What are the sensory symptoms of peripheral neuropathies?
sensory loss, paresthesias
large sensory fiber involvement = deficits in vibration and proprioception
small fiber involvement = pain and temperature perception
132
What diagnostic tools are useful for evaluating peripheral neuropathy?
serum studies
CSF examination
nerve conduction studies
nerve biopsy
133
What is the pathophysiology of acute inflammatory demyelinating polyneuropathy?
molecular similarity between myelin proteins and glycolipids expressed by several infectious agents, so antibodies against these agents may cross react with specific antigens on the Schwann cells and myelin --\> results in cascade activation, lysis of myelin sheaths, inflammation
134
What are the clinical features of acute inflammatory demyelinating polyneuropathy?
progressive, fairly symmetric proximal and distal weakness with absent or depressed deep tendon reflexes
autonomic and respiratory involvement common
symptoms peak by week 4
135
What are the lab/study findings associated with acute inflammatory demyelinating polyneuropathy?
lab: elevated CSF protein with normal WBC count
nerve conduction studies: slowed conduction velocities (segmental demyelination)
136
What are the treatments for acute inflammatory demyelinating polyneuropathy?
plasma exchange or IVIg
supportive care
**not corticosteroids**
137
What is chronic inflammatory demyelinating polyneuropathy? What is the treatment?
chronic immune-mediated polyneuropathy, progresses for greater than eight weeks
treatment: IVIg or corticosteroids or other immunomodulating medications, supportive care
138
What is charcot-marie-tooth disease type 1?
a spectrum of disorders caused by a specific mutation in one of seberal myelin genes that results in defects of myelin structure, maintenance, and formation
139
What are the clinical features of carcot-marie-tooth disease type 1?
distal calf muscle atrophy --\> stork leg deformity
clumsy walking (weakness and sensory loss that is gradual and mainly involves proprioception and vibration)
140
What endocrinopathies are associated with neuropathy?
diabetes mellitus, hypothyroidism
141
What systemic diseases are associated with neuropathy?
connective tissue disease, IBD, liver disease, uremia
142
What nutritional deficiencies are associated with neuropathy?
vitamin (B12, B6, vitamin E)
copper, phosphate
alcohol
143
What infections are associated with neuropathies?
viral: HIV, HTLV-1, hep B and C
bacterial: lyme, leprosy
144
What is the most common presentation of diabetic polyneuropathy?
distal symmetric sensory polyneuropathy
length dependent affecting both small and large fibers
145
What is the treatment for diabetic polyneuropathy?
tight blood sugar control and symptom management
146
What is the presentation of neuropathy associated with vitamin B12 deficiency?
CNS and/or PNS abnormalities, dysfunction of posterior columns and/or corticospinal tracts
leads to reduced vibratory and proprioception with spastic paraparesis
147
Which type of neuropathy requires pain management?
small fiber (large fiber leads to numbness, not pain)
148
What fibers are affected by large fiber neuropathy?
myelinated A-beta fibers (proprioception, fine touch, vibration)
myelinated A-alpha fibers (motor strength)
149
What is Guillain-Barre Syndrome?
an acute demyelinating polyneuropathy with ascending paresis and sensory changes
150
What gene is associated with MS?
polymorphisms of the major histocompatibility complex
151
What is the pathology of multiple sclerosis?
involves gray and white matter regions
areas of demyelination and axonal loss, associated with inflammatory lymphocytes and activated macrophages
152
What type of lymphocytes predominate in MS plaques? Perivascular distribution?
Plaques: CD8+ T lymphocytes, plasma cells, B lymphocytes
Perivascular distribution: CD4+ T lymphocytes
153
What is the pathophysiology of MS?
demyelinated axons = slowed/blocked signal transmission that disrupts conduction of nerves
sodium channels are elaborated to maintain conduction, but there is an increased metabolic demand and it is slower
154
What are the clinical features of MS?
symptoms organized around relapses and exacerbations
common symptoms: sensory changes, vision loss, weakness, spasticity, cerebellar dysfunction, neurologic symptoms, cognitive impairment, etc
155
What is L'Hermitte's sign?
brief electrical shock-like sensation momentarily down the spine triggered by neck flexion
156
What is Uthoff's phenomenon?
recurrent visual blurring in a patient with previous optic neuritis
157
What are pseudo-relapses of MS?
recurrent symptoms provoked by fever or intercurrent ilness that may mimic exacerbations, but do not require anti-inflammatory treatment
158
What is relapsing-remitting MS?
A form of MS that presents with an attack of symptoms followed by complete or partial symptomatic recovery
159
What is primary vs. secondary progressive MS?
primary MS = disease that progresses from the onset
secondary MS = progressive worsening later in course of disease
160
What are "Dawson's fingers"?
lesions seen on MRI that are ovoid and perpendicular to the ventricles
161
What is the most useful imaging technique for MS?
MRI
162
What is neuromyelitis optica spectrum disorder?
A disease similar in presentation to MS with longitudinally extensive spinal cord lesions and is often positive for NMO/AQP4 - IgG antibody
163
What is acute disseminated encephalomyelitis?
A post-infectious or post-vaccination demyelinating event associated with headache, seizures, and mental status change. MRI shows extensive brain lesions and longitudinally extensive spinal cord lesions
164
What are the treatments for multiple sclerosis (generally)?
disease modifying therapies
managing symptoms
wellness and co-morbidities (weight loss, stopping smoking, dietary changes)
165
Which of the following factors is not associated with an increased risk of developing multiple sclerosis?
a) low vitamin D levels
b) alcohol use
c) tobacco smoking
d) residence in temperature latitudes
b) alcohol use
166
Which of the mechanisms is not considered to be a pathologic feature of multiple sclerosis?
a) innate immune activation
b) axon damage due to metabolic stress
c) loss of Schwann cells
d) elaboration of increased sodium channels in demyelinated axons
c) loss of Schwann cells
167
Diagnosis of MS using the McDonald 2017 criteria requires which of the following?
a) typical lesions in multiple characteristic locations in the CNS
b) typical lesions in characteristic locations occurring at different times
c) typical lesion in characteristic locations at one time point and unique CSF oligoclonal bands
d) any of the above
e) a and b
d) any of the above
168
Typical acute CNS demyelinating symptoms include all of the following except?
a) optic neuritis
b) partial myelitis
c) abrupt onset of hemiparesis
d) double vision
e) balance impairment
c) abrupt onset of hemiparesis
169
Neuromyelitis optic spectrum disorder is not associated with which of the following?
a) blood test positive for anti-MOG antibody
b) blood test positive for aquaporin 4 antibody
c) gradually progressive neurologic disability
d) presentation with acute attacks resulting from lesions in the brainstem
c) gradually progressive neurologic disability
170
